Thread guiding means for yarn winding

ABSTRACT

A thread guide for a yarn winding machine, which comprises a reciprocating shuttle slidably mounted on a fixed track and means for subjecting the shuttle to timed blasts of compressed air to cause its reciprocating movement along the track. The shuttle is a double-acting cylinder member having opposed open-ended cylinders which cooperate with fixed pistons mounted in adjustable positions at opposite ends of the track. The fixed pistons contain poppet valves arranged to be actuated by the engagement of the shuttle with their actuating members at the ends of the reciprocating movements of the shuttle along the track. Each actuating member protrudes from the crown of one of the fixed pistons for engagement by the end wall of the opposed cylinder of the shuttle and when so engaged opens the valve to deliver a blast of compressed air into the cylinder to propel the shuttle in the reverse direction along the track.

United. States Patent Burgess et al.

- June 22, I970 THREAD GUIDING MEANS FOR YARN WINDING lnventors: JohnLeslie Burgess, Penzance,

Cornwall; Joseph Eric Harvey, Camborne, Cornwall, both of EnglandAssignee: Maxam Power Limited, Camborne,

Cornwall, England Filed: Aug. 19, 1970 Appl. No.: 65,296

Foreign Application Priority Data Great Britain ..30,207/70 US. Cl...242/43, 242/1 8.1, 242/43.l

Int. Cl. ..B65h 54/28 Field of Search ..242/43,. 43.1, 18.1

References Cited UNITED STATES PATENTS Dyer et al. ..242/43 Dyer..242/43 Dyer ..242/43 Emerson ..242/43 1451 Sept. 26, 1972 3,1 18,628l/l964 Lacasse ..242/43 Primary Examiner-Stanley N. GilreathAttorney-Watson, Cole, Grindle & Watson 57] ABSTRACT A thread guide fora yarn winding machine, which comprises a reciprocating shuttle slidablymounted on a fixed track and means for subjecting the shuttle to timedblasts of compressed air to cause its reciprocating movement along thetrack. The shuttle is a doubleacting cylinder member having opposedopen-ended cylinders which cooperate with fixed pistons mounted inadjustable positions at opposite ends of the track. The fixed pistonscontain poppet valves arranged to be actuated by the engagement of theshuttle with their actuating members at the ends of the reciprocatingmovements of the shuttle along the track. Each actuating memberprotrudes from the crown of one of the fixed pistons for engagement bythe end wall of the opposed cylinder of the shuttle and when so engagedopens the valve to deliver a blast of compressed air into the cylinderto propel the shuttle in the reverse direction along the track.

14 Claims, 4 Drawing Figures SHEET 1 OF 4 PATENTEDSWB I972 INVENTORSLESLIE Bukasss Em: HAaveY BY M Mw ATTORNEY PATENTED SEP 26 I972 SHEET 3[IF 4 Wm vv mv B mm R INVENTORS LEN-E Bulzecss ATTORNEY THREAD GUIDINGIWEAN S FOR YARN WINDING This invention relatesv to machines for windingyarn on,a rotating spool or bobbin, and is concerned with providing suchmachines with an improved form of thread guiding means.

In the conventional winding of yarn'on a spool or bobbin, the thread iswound in layers each comprising an extremely coarse helix, to form aso-called package on the spool, the thread being'guided onto the spoolduring the winding by a mechanically driven cam-controlled reciprocatingguide arm which guides the-thread along the axial length of the spooland back again as the spool rotates. The speed at which such yarnwinding machines can work is limited by the maximum speed at which thecam-operated thread guide can be reciprocated, the practical limit atpresent being 600-700 complete cycles per minute, i.e., l,200-l-,400one-way strokes per minute. Moreover, when such purely mechanical threadtransporting mechanisms are run at high speed, very considerablestresses arise due to the high accelerations and decelerations involvedin the rapidreversals of direction of the moving parts, so

that mechanical wear is considerable.

One object of the present invention is to provide a yarn-winding machinehaving a thread guide which can be reciprocated at much higher speedsthan this without excessive wear, and which is readily adjustable tovary the length of stroke, for example during the act ual high-speedwinding operation, to suit the particular size or shape of wound packagerequired.

According to the present invention, a high-speed pneumatic traverse forleading yarn on to a rotary takeup spool of a yarn-winding machine whilereciprocating the yarn transversely across the face of the spool,comprises a linear track extending across the face of the take-up spool,a linearly-reciprocable shuttle slidably mounted on the track forreciprocating movement along the track, a thread guide carried by theshuttle,

means for applying compressed air alternately to opposite ends of theshuttle to propel the shuttle pneumatically along the track insuccessively reversed reciprocation strokes, which means comprises apair of valve housings respectively mounted at opposite ends of thetrack, means for connecting both valve housings to a supply ofcompressed air, a pneumatic control valve in each valve housing, eachcontrol valve being biassed to a closed position and having an actuatingmember positioned to be actuated by the moving shuttle approaching therespective valve housing toward the end of a reciprocating stroke, theactuating member when so actuated opening the control valve to release ablast of compressed air which reverses the direction of motion of theshuttle and propels the shuttle along the track in its next-succeedingreciprocation stroke, and in which each valve housing is mounted formovement along the length of track during the operation of the traversedevice, and which includes a strokeadjusting mechanism coupled to bothvalve housings and operable to move both valve housings progressivelytoward-one another along a track at a controlled rate during thereciprocating motion of the shuttle so as to reduce the stroke length ofthe shuttle progressively during the operation of the winding machine.

In one form of the invention, the stroke-adjusting mechanism comprisesan actuator member and a pair of driving mechanisms respectively coupledbetween said actuator member and the respective valve housings wherebymovement of the said actuator member in a given direction causes the twovalve housings to be moved toward one another along the track.

A further object of the invention is to provide means for breaking thepattern of the yarn on the winding as the latter builds up progressivelyon the take-up spool, and for this purpose means is provided for rapidlyshifting the position of each of the valve housings along-the track atintervals during the winding operation for pattem-breaking purposes, thesaid pattern-breaking means overriding the actuation of thestroke-adjusting mechanism, and preferably comprising a motor-drivenrotary cam mechanism coupled to both of the said valve housings.

A still further object of the invention is to provide an improvedconstruction of control valve in each valve housing of the traversedevice. For this purpose each valve housing and the associated end ofthe shuttle may be constructed and arranged to telescope one within theother as a free-fitting piston-and-cylinder mechanism, and to enclose aspace between them when so telescoped, the control valve when openeddelivering compressed air into said enclosed space to act on the end ofthe shuttle, and each control valve may have a valve seating and acooperating movable valve plunger aligned with the track, the plungerbeing formed with opposed piston faces respectively subject tooppositely directed differentially acting nearly balanced pressurethrusts by the compressed air supply connected to the valve housing andbeing biassed to its closed position in engagement with the valveseating, and an end portion of the plunger protruding from the valvehousing toward the other valve housing and constituting the actuatingmember for engagement by the shuttle, whereby the initial engagement ofsaid protruding end of the plunger by the shuttle partially opens thevalve to deliver compressed air to said enclosed space between thetelescoped valve block and shuttle end, whereupon the pressure of thecompressed air delivered into said enclosed space acts on saidprotruding end of the plunger to open the valve fully. Thus when thecontrol valve is cracked open by the engagement of the shuttle at theend of its approach stroke, the air delivered through the partiallyopened valve and acting on the shuttle to reverse its direction ofmotion will be at high pressure, and this high air pressure acting onthe plunger of the poppet valve will at once fully open the valve. Whenthe shuttle has reversed its travel and has been propelled in theopposite direction by the air pressure into its succeeding stroke, thepressure of air delivered through the open poppet valve will fall toatmospheric pressure, and the poppet valve will be reclosed by itsclosing spring.

In one arrangement of the invention the shuttle is slidably mountedbetween rigid elongated parallel guides having the fixed pistonpositioned between them. For example the parallel guides may compriserods threaded through apertures in opposite sides of the shuttle, sothat the shuttle can slide along the rods between which it is suspended.Alternatively, the guides may comprise a pair of spaced parallelinwardly facing channel guides of part-circular or other internalcross-section corresponding to the external cross-sec- 3 tional profileof the shuttle, the shuttle being slidably mounted in the opposedchannels of the two guides.

The invention may be carried into practice in various ways but onespecific embodiment and a modification thereof will now be described byway of example only and withzreference to the accompanying drawings, inwhich g t FIG."1 is an end elevation of ayarn winding machine,

FIG. 2 is a plan'view of the machine of FIG. 1 with certain partsomitted for the sake of clarity,

FIG. 3 is a detailedview, partly sectioned and on a larger scale, of thethread guide means for the winding machine of FIGS. 1 and 2, and v IFIG. 4 is a perspective view of a modified construction of a threadguide means.

Y The winding machine of FIGS. 1 and 2 comprises a frame on which atake-'upspool or former 11 fora winding package 12 isjournalled in endbearings 13. The'package 12,"which is shown partly wound in FIG. 1, isdriven at a constant peripheral speed by means of a friction roller 14journalled on one end of an arm 15 whose other end is pivoted at 16 tothe frame 10, the roller 14 being'driven by a belt drive 17 from anelectric motor 18. The friction roller 14 can pivot on the 15 as thediameterof the package 12 grows during the winding process, from-astarting position shown in broken lines in FIG. 1' to the intermediateposition shown in firm lines, and beyond, so that the peripheral speedof the rotating package 12 will remain in constant ratio to the speed ofthe driving motor 18 despite the changing radius of the package. Thedriving roller 14, arm 15, belt drive 17 and. motor 18 and the frame 10,have all been omitted from FIG. 2 for the sake of clarity. Y Y

The yarn 20 for windingon the package-is led down vertically from anoverhead supply (notshown) and is guided onto the package 12 by thereciprocating forked guide plate 21 of a thread guide mechanism which isgenerally indicated at 22 and is shown in detail in FIG. 3. The threadguide mechanism 22 is mounted on the upper edge of a swinging frame 23pivoted to the frame 10 at 24. The'swinging frame 23 carries anelongated roller 25 which holds the vertical yarn 20 against the packageduring winding-the pressure of the yarn on the roller 25 swinging theframe 23 and the guide mechanism 22 outwardly as the radius of thepackage grows during the winding.

The thread guide shown in detail in FIG. 3 comprises a shuttle 30slidably mounted for reciprocating motion along a pair of spacedparallel guide rods 31, 31 secured across the arms 23A of the swingingframe 23 and tensioned by means of nuts 33. The shuttle 30 comprises adouble-acting cylinder member whose two coaxial cylinders 35 have theiropen ends facing outwardly at opposite ends of the shuttle and are bothclosed at their inner ends by walls 36. The shuttle 30 carries thethread guide plate 21 in which is inset a thread guide 37 made of somehard sintered material such as aluminum oxide.

The shuttle cylinders 35 co-operate respectively with a pair of fixedbut longitudinally-adjustable pistons 38 formed as projecting bosses onthe ends of a pair of spaced housings 39 each of which is slidablymounted on the guide rods 31 and is carried on one end of a backing rod40. Each housing 39 has a cylindrical bore in whicha valve plunger 41 isa close sliding fit, the plunger 41' forming the movable valvemember ofa poppet valve. The head 43 of the poppet valve plunger 41 carries asealing ring 44 which co-operates with a valve seating formed on aninturned flange 45 at the inner end of the piston 38, and a light spring46 acting on the rear end of the valve plunger 41 tends to hold thepoppet valve seal 44 in sealing engagement with the seating to close thepoppet valve. An actuating button 48 on the other end of the plunger 41protrudes through the aperture defined by the flange 45 and can bedepressed to open the poppet valve. Compressed air is admitted through apipe 50 into the bore of the housing.39 and into an annular groove 51 inthe plunger 41 so as to be retained by the poppet valve seal 44 when thevalve is closed. The compressed air can pass through axial'grooves 52 ina land 53 on the valve plunger 41' so as to reach the head 43 of theplunger. The effective face area of thepiston face constituted by theland 53 is slightly larger than the effective face area of the poppetvalve head 43, so that the differential pressure of compressed airadmitted through the pipe 50 would openthe poppet valve but for. thespring 46, which holds the valve lightly closed with the valve seal 44engaging the valve-seat on the flange 45. A very small force exerted onthe actuatingbutton 48 however will overcome the spring 46 and open thepoppet valve. The housing 39 is formed with a vent 54 leading from itsbore behind the plunger 41 to relieve pressure behind the plunger due toany leakage of compressed air past the plunger.

Each shuttle cylinder 35 is a loose fit around the associated piston 38,the radial clearance being 0.l mm approximately, which is sufficient toeliminate cushioning of the shuttle by air trapped between the piston 38and cylinder 35, and to eliminate piston/cylinder wear almost entirelyas no actual contact is made between the cylindrical surfaces of thepistons andcylinders. The axial projection of each actuating button 48beyond the crown of the associated piston 38 is very small, forexampleO.5 mm., so that when the shuttle 30 reaches the end of itsstroke the engagement of the inner end wall36 of onecylinder 35 with theactuating button 48 protruding from the piston 38 which has entered thatcylinder is sufficient to open the poppet valve very slightly.

The operation of the mechanism will now be described from that pointonwards. When the poppet valve has been cracked open by this depressionof the actuating-button 48 by the shuttle 30 at the end of one stroke,compressed air supplied from the pipe 50 passes through the grooves 52and escapes past the seal 44 of the slightly open poppet valve into theshuttle cylinder 35 to act on the shuttle 30. The pressure of thecompressed air trappedin the cylinder 35 acts on the full effective facearea of the piston land 53 and the end of the plunger 41 and immediatelyforces the poppet valve plunger 41- right back off its seat on theflange 45 to open the valve fully, enabling a full flow of compressedair from the supply pipe 50 to enter the cylinder 35 and to act on theshuttle 30, to stop the forward travel of the shuttle and to accelerateit rapidly in the opposite direction. As soon as the cylinder 35 clearsthe piston 38 in an early stage of the reversed travel of the shuttle30, the air pressure acting on the plunger 41 to hold the poppet valveopen will drop to atmospheric pressure, allowing the poppet valve to beclosed by the spring 46.

- The shuttle continues to travel along the guide rails '31 for afurther complete stroke, until it reaches the piston 38 at the oppositeend of the rails 31 and actuates the button 48 of that piston to openthe associated poppet valve and initiate a further reversal of travel ofthe shuttle. In this way the cycle of movement of the shuttle 30 iscompleted and continuous reciprocating motion of the shuttle along theguide rails is maintained,'the operation of the poppet valves whichcontrol the supply of compressed air being automatically synchronizedwith the movement of the shuttle by virtue of the fact that the shuttleitself initiates the opening of the poppet valves.

' To start the reciprocating movement of the shuttle 30, the shuttle isflicked manually against the actuating button 48 of one or other of thefixed pistons 38, thereby cracking open the associated poppet valve toinitiate the compressed air: supply. Thereafter the reciprocationcontinues automatically.

Thelength of stroke of the shuttle is determined by the spacing betweenthe actuating buttons v48 of the two fixed pistons 38. This spacing canbe adjusted by means of a slow stroke-reducing mechanism including.a'pair of spaced cams 60 shown in FIG. 2,-whose cam followers 61 aremounted on the ends of the backing rods 40. The cams 60(which areomitted from FIG. 1 for the sake of clarity) are slidably mounted onguide rods 62 carried by the fixed journal bearings 13 for the take-upspool 11. The backs 63 of the cams 60 are plane, and are engaged byadjustable stops 64 each of which when in a given position of adjustmentbears against the back 63 of the associated cam 60 to hold the cam in agiven position on its guide rod 62. As the winding process proceeds andthe radius of the package 12 grows, the engagement of the guide roller25 with the periphery of the" growing package progressively swings thepivotedframe 23 outwardly so 'as to move the-whole thread guidemechanism 22 on theframe 23 transversely to its length in the directionaway from the take-up spool 11. This movement causesthe two camfollowerrollers-61 on the backing rods 40 to traverse the profiles ofthe cams 60 whereby the backing rods 40 are slowly and progressivelycammed towards one another, sliding through the ends 23A of the frame 23as the winding proceeds. This movement of the backing rods 40 produces acorresponding movement towards one another at a controlled rate of thehousings 39,

slidingalong the guide rods 31 whereby the spacing between the fixedpistons 38 and hence the stroke of the shuttle reciprocation are slowlyand progressively reduced, at a controlled rate, in order to produce therequired tapered ends. of the package of yarn being wound. t I

A periodic abrupt shortening of the shuttle stroke can also besuperimposed on the slow stroke reduction for the purpose known aspattern breaking- Such abrupt stroke shortening is produced by means ofa further'cam 70 which is mounted on the vertical shaft of a gear box 71driven by means of an electric motor 72, the gtiar box and motor beingmounted on the main frame 10 behind the swinging frame 23. The cam 70acts on apairof cam followers 73each mounted on a piston 74 slidable ina horizontal tubular guide sleeve 75 above the gear box 71, each camfollower 73 projecting downwardly through a longitudinal slot in thelower wall of the guide sleeve 75. Each piston 74 is secured to thecentral sliding core 76 of one of a pair of flexible control cables 77which extend between the ends of the guide sleeve 75 and-the ends of thethread guide mechanism and are coupled to the movable stop plungers 64.Thus the rotation of the cam; by the motor 72 (which may be controlledin synchronism with the winding motor 18) periodically transmits theinward motion through each flexible cable 77 to the associated stopplunger 64,v by which motion the associated cam 60 is abruptly movedinwardly above the guide rod 62 to shorten the stroke of the shuttle 30at that end of the mechanism, thereby ensuring a change in the lay ofthe turns of yarn in the winding of the package and achieving therequired pattern breaking.

The movable stop plungers 64 are mounted in bores formed in a pair ofbrackets 78 to which the ends of the outer sleeves of the flexiblecables 77 are connected. Each bracket 78 is slidably mounted formovement along a slideway formed in the back of the frame 23 and can be.clamped in a required position by means of bolts 79. Thus for effectinga preliminary adjustment of the basic stroke length of the shuttle uponwhich the automatic variation produced by the cams 60 and 70 will beimposed, the brackets 78 can be moved individually along the slideway ofthe frame 23 to suitable positions at a required spacing, and secured inthese positions of adjustment by means of the bolts 79.

It will be understood that slow stroke-adjustment cams andpattern-breaking cams similar to the cams 60 and 70 are provided inconventional yarn winding machines already in use with conventionalmechanically-driven thread guides.

l-lowever, the arrangement described and illustrated enables these twostroke-shortening movements to be imposed on the pneumatically'driventhread transport means of the present invention while the latter isbeing driven at very high speeds of reciprocation, whereby packages withtapered ends can be wound at high speed, which was not possible with theknown machine having mechanically driven thread guide arrangements. Thisis particularly important where the yarn being wound is a heat-processedthermoplastic material which tends to swell after winding, and if woundin straight-ended packages tends to fall off the ends of the package.

The arrangement also provides very accurate control of stroke length andof the position of the shuttle 30 when stationary at the end of eachstroke, by virtue of the very short length of each actuating button 48protruding from its piston 38, ensuring accurate cracking of the poppetvalves followed by automatic full opening of the valves by the resultantpneumatic delivery pressure. Location of the end points of shuttletravel of the order of accuracy of i 0.2 mm can be obtained withoutdifficulty.

The substantial piston/cylinder clearance of approximately 0.1 mm allround also contributes to accuracy of these end points, by eliminatingcushioning of the shuttle by trapped air, and this increased clearanceeliminates wear at the piston/cylinder interface and increases theuseful life of the shuttle.

As the thread guide device is self-synchronizing, stroke reduction canbe achieved with absolute reliability and without risk of stalling thereciprocation of the shuttle, and the improved synchronization enablesthe device to operate reliably on a low air pressure for a givenspeed ofreciprocation, thereby reducing noise and consumption of compressed air.An almost constant helix angle is maintained during winding at constantlinear yarn speed so that the circumferential velocity/transversevelocity ratio remains practically constant as the package grows. Thishelps to produce a stable package of good appearance. a In amodification of thread guide mechanism 22A illustrated in FIG. 4, theshuttle 30A instead of being slidably mounted on two spaced parallelguide rails, is

slidably mounted between two spaced parallel inwardly facing elongatedchannel'guides 71A and 72A of semicircular or other convenient internalcross-section. One channel guide 7lA-is constructed and arranged so asto be easily disconnected and lifted off, to allow the rapid replacementof the, shuttle 30A. The valve housings 39A are similarly slidablymounted, between the two channel members, and other parts of themechanism are similar in their construction and'operation to those ofthe preceding embodiment, and are identified in FIG; 4 by the samereference numerals distinguished by thesuffixA.'. v I The thread guidemechanism 22A would be substituted for the mechanism 22 in a windingmachine as shown in FIGS. 1 and 2. What we claim as our invention anddesire to secure by Letters Patent is: I

I l. A high-speed pneumatic traverse device'for leading yarn on toarotary take-up spool of a yam-winding machine by reciprocating the yarntransversely across the face of the spool, which comprisesa linear trackextending across the' face'of the take-up spool, a linearly reciprocableshuttle slidably mounted'on the track for reciprocating movementtherealong, a thread guide carried by the shuttle, means for applyingcompressed 2. A pneumatic traverse device as claimed in claim 1 in whichthe stroke-adjusting mechanism comprises a control member and a pair ofdriving mechanisms respectively coupled to the valve housings wherebymovement of said control member in a given direction causes the twovalve housings to be moved toward one another along the track.

3. A pneumatic traverse device as claimed in claim 2 including means formoving said control memberautomatically in response to the increase inradius of a packageof yarn being wound on the take-up spool, whereby thetwo valve housings are moved toward one another proportionately to theincrease in radius to form a package with tapering ends.

' 4. A pneumatic traverse device as claimed in claim 3 in which thetrack is mounted on a carrier pivotally mounted for movement toward andaway from the take-up spool, and which includes a roller carried by thecarrier for engagement with the external surface of the package of yarnbeing wound on the take-up spool,

' whereby the carrier is moved angularly relatively to the take-up spoolin relation upon the increase in radius of air alternately to oppositeendsof the shuttle to propel v moving shuttle approaching the respectivevalve housing towards the end of a reciprocating stroke, the actuatingmember when so actuated opening the control valve to release a blast ofcompressed air which reverses the direction of motion of the shuttle andpropels the shuttle along the track in its next-succeeding reciprocationstroke, and in which each valve housing is mounted for movement alongthe length of the track during the operation of the traverse device, andwhich includes a stroke-adjusting mechanism coupled to both valvehousings and operable to move both valve housings progressively towardone another along the track at a controlled rated during thereciprocating motion of the shuttle so as'to reduce the stroke length ofthe shuttle progressively during the operation of the winding machine.

thepackage, the carrier constituting said control member.

5. A pneumatic traverse device as claimed in claim 4 in which each saiddriving mechanism comprises a cam,

and a cam follower coupled to the associated valve housing.

6. A pneumatic traverse device as claimed in claim 5 in which said camscomprise a pair of edge cams, each attached to a support for the take-upspool, and in which each said driving mechanism also includes a followerroller carried bythe associated valve housing, and. an adjustablymounted backing member, each edge cam being interposed between theassociated follower roller and backing member and camming the valvehousing away from the backing member and toward the other valve housingas the carrier is moved angularly away from the take-up spool.

7. A pneumatic traverse device as claimed in claim 6 in which thetwo'edgecams are both slidable on the support for the take-up spool in adirection parallel to the length of the track, and which includespatternbreaking means for rapidly moving one of the adjustably-mountedbacking members through a short distance in a direction parallel to thelength of the track to effect a rapid shifting of the associated edgecam and valve housing for pattern-breaking purposes.

8. A pneumatic traverse device as claimed in claim 1 includingpattern-breaking means for rapidly shifting the position of each of thevalve housings along the track at intervals during thewincling operationfor patconnecting to the valve housing and being biassed to its closedposition in engagement with the valve seating, and an end portion of theplunger protruding'from the valve housing toward the other valve housingand constitutingthe actuating member for engagement by the shuttle,whereby the initial engagement of said protruding end of the plunger bythe shuttle partially opens the valve to deliver compressed air to theenclosed space between the telescoped valve block and shuttle end,whereupon the pressure of the compressed air delivered into the enclosedspace acts on said protruding end of the plunger to open the valvefully.

'12. A pneumatic traverse device as claimed in claim 1 in which theshuttle comprises a double-acting cylinder member whose two endscomprise a pair of oppositely'facing aligned cylinders whose outer endsare open, which cylinders cooperate respectively with a pair of pistonsaligned with the track and forming parts of the respective valvehousings, each piston entering the respective shuttle cylinder withclearance between them at the end of a reciprocation stroke of theshuttle in a corresponding direction, and in which the actuating memberof each control valve protrudes through the outer end face of therespective piston for engagement by the inner end face of the associatedcylinder of the shuttle.

13. A pneumatic traverse device as claimed in claim 12 in which thetrack comprises a pair of rigid parallel guide rails on which theshuttle is slidably mounted, the shuttle and the fixed pistons lyingbetween the guide rails.

14. A pneumatic traverse device as claimed in claim 12 in which thetrack comprises a pair of spaced parallel elongated channel-sectionguides whose channels face toward one another and together define anelongated guide passage of a cross-section corresponding to the externalcross-sectional profile of the shuttle, the shuttle being slidable inthe opposed channels of the two guides.

1. A high-speed pneumatic traverse device for leading yarn on to arotary take-up spool of a yarn-winding machine by reciprocating the yarntransversely across the face of the spool, which comprises a lineartrack extending across the face of the take-up spool, a linearlyreciprocable shuttle slidably mounted on the track for reciprocatingmovement therealong, a thread guide carried by the shuttle, means forapplying compressed air alternately to opposite ends of the shuttle topropel the shuttle pneumatically along the track insuccessively-reversed reciprOcation strokes, which means comprises apair of valve housings respectively mounted at opposite ends of thetrack, means for connecting both valve housings to a supply ofcompressed air, a pneumatic control valve in each valve housing, eachcontrol valve being biassed to a closed position and having an actuatingmember positioned to be actuated by the moving shuttle approaching therespective valve housing towards the end of a reciprocating stroke, theactuating member when so actuated opening the control valve to release ablast of compressed air which reverses the direction of motion of theshuttle and propels the shuttle along the track in its next-succeedingreciprocation stroke, and in which each valve housing is mounted formovement along the length of the track during the operation of thetraverse device, and which includes a stroke-adjusting mechanism coupledto both valve housings and operable to move both valve housingsprogressively toward one another along the track at a controlled ratedduring the reciprocating motion of the shuttle so as to reduce thestroke length of the shuttle progressively during the operation of thewinding machine.
 2. A pneumatic traverse device as claimed in claim 1 inwhich the stroke-adjusting mechanism comprises a control member and apair of driving mechanisms respectively coupled to the valve housingswhereby movement of said control member in a given direction causes thetwo valve housings to be moved toward one another along the track.
 3. Apneumatic traverse device as claimed in claim 2 including means formoving said control member automatically in response to the increase inradius of a package of yarn being wound on the take-up spool, wherebythe two valve housings are moved toward one another proportionately tothe increase in radius to form a package with tapering ends.
 4. Apneumatic traverse device as claimed in claim 3 in which the track ismounted on a carrier pivotally mounted for movement toward and away fromthe take-up spool, and which includes a roller carried by the carrierfor engagement with the external surface of the package of yarn beingwound on the take-up spool, whereby the carrier is moved angularlyrelatively to the take-up spool in relation upon the increase in radiusof the package, the carrier constituting said control member.
 5. Apneumatic traverse device as claimed in claim 4 in which each saiddriving mechanism comprises a cam, and a cam follower coupled to theassociated valve housing.
 6. A pneumatic traverse device as claimed inclaim 5 in which said cams comprise a pair of edge cams, each attachedto a support for the take-up spool, and in which each said drivingmechanism also includes a follower roller carried by the associatedvalve housing, and an adjustably mounted backing member, each edge cambeing interposed between the associated follower roller and backingmember and camming the valve housing away from the backing member andtoward the other valve housing as the carrier is moved angularly awayfrom the take-up spool.
 7. A pneumatic traverse device as claimed inclaim 6 in which the two edge cams are both slidable on the support forthe take-up spool in a direction parallel to the length of the track,and which includes pattern-breaking means for rapidly moving one of theadjustably-mounted backing members through a short distance in adirection parallel to the length of the track to effect a rapid shiftingof the associated edge cam and valve housing for pattern-breakingpurposes.
 8. A pneumatic traverse device as claimed in claim 1 includingpattern-breaking means for rapidly shifting the position of each of thevalve housings along the track at intervals during the winding operationfor pattern-breaking purposes, said pattern-breaking means beingarranged to override the actuation of the stroke-adjusting mechanism. 9.A pneumatic traverse device as claimed in claim 8 in which saidpattern-breaking means comprises a motor-driven rotary cam mechanismcoupled to both of said valve housings.
 10. A pneumatic traverse deviceas claimed in claim 1 in which each valve housing and the associated endof the shuttle are constructed and arranged to telescope one within theother as a free-fitting piston-and-cylinder mechanism, and to enclose aspace between them when so telescoped, the control valve when openeddelivering compressed air into said enclosed space to act on the end ofthe shuttle.
 11. A pneumatic traverse device as claimed in claim 10 inwhich each control valve is a poppet valve having a valve seating and acooperating movable valve plunger aligned with the track, the plungerbeing formed with opposed piston faces respectively subject tooppositely directed differentially acting nearly balanced pressurethrusts by the compressed air supply connecting to the valve housing andbeing biassed to its closed position in engagement with the valveseating, and an end portion of the plunger protruding from the valvehousing toward the other valve housing and constituting the actuatingmember for engagement by the shuttle, whereby the initial engagement ofsaid protruding end of the plunger by the shuttle partially opens thevalve to deliver compressed air to the enclosed space between thetelescoped valve block and shuttle end, whereupon the pressure of thecompressed air delivered into the enclosed space acts on said protrudingend of the plunger to open the valve fully.
 12. A pneumatic traversedevice as claimed in claim 1 in which the shuttle comprises adouble-acting cylinder member whose two ends comprise a pair ofoppositely facing aligned cylinders whose outer ends are open, whichcylinders cooperate respectively with a pair of pistons aligned with thetrack and forming parts of the respective valve housings, each pistonentering the respective shuttle cylinder with clearance between them atthe end of a reciprocation stroke of the shuttle in a correspondingdirection, and in which the actuating member of each control valveprotrudes through the outer end face of the respective piston forengagement by the inner end face of the associated cylinder of theshuttle.
 13. A pneumatic traverse device as claimed in claim 12 in whichthe track comprises a pair of rigid parallel guide rails on which theshuttle is slidably mounted, the shuttle and the fixed pistons lyingbetween the guide rails.
 14. A pneumatic traverse device as claimed inclaim 12 in which the track comprises a pair of spaced parallelelongated channel-section guides whose channels face toward one anotherand together define an elongated guide passage of a cross-sectioncorresponding to the external cross-sectional profile of the shuttle,the shuttle being slidable in the opposed channels of the two guides.